Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * mount.c - operations for initializing and mounting sysfs. | |
3 | */ | |
4 | ||
5 | #define DEBUG | |
6 | ||
7 | #include <linux/fs.h> | |
8 | #include <linux/mount.h> | |
9 | #include <linux/pagemap.h> | |
10 | #include <linux/init.h> | |
94bebf4d | 11 | #include <asm/semaphore.h> |
1da177e4 LT |
12 | |
13 | #include "sysfs.h" | |
14 | ||
15 | /* Random magic number */ | |
16 | #define SYSFS_MAGIC 0x62656572 | |
17 | ||
18 | struct vfsmount *sysfs_mount; | |
19 | struct super_block * sysfs_sb = NULL; | |
e18b890b | 20 | struct kmem_cache *sysfs_dir_cachep; |
1da177e4 | 21 | |
ee9b6d61 | 22 | static const struct super_operations sysfs_ops = { |
1da177e4 | 23 | .statfs = simple_statfs, |
b592fcfe | 24 | .drop_inode = sysfs_delete_inode, |
1da177e4 LT |
25 | }; |
26 | ||
51225039 | 27 | struct sysfs_dirent sysfs_root = { |
13b3086d | 28 | .s_count = ATOMIC_INIT(1), |
b402d72c | 29 | .s_flags = SYSFS_ROOT, |
fc9f54b9 | 30 | .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
dc351252 | 31 | .s_ino = 1, |
1da177e4 LT |
32 | }; |
33 | ||
34 | static int sysfs_fill_super(struct super_block *sb, void *data, int silent) | |
35 | { | |
36 | struct inode *inode; | |
37 | struct dentry *root; | |
38 | ||
39 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
40 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
41 | sb->s_magic = SYSFS_MAGIC; | |
42 | sb->s_op = &sysfs_ops; | |
43 | sb->s_time_gran = 1; | |
44 | sysfs_sb = sb; | |
45 | ||
e080e436 TH |
46 | /* get root inode, initialize and unlock it */ |
47 | inode = sysfs_get_inode(&sysfs_root); | |
fc9f54b9 | 48 | if (!inode) { |
1da177e4 LT |
49 | pr_debug("sysfs: could not get root inode\n"); |
50 | return -ENOMEM; | |
51 | } | |
52 | ||
fc9f54b9 TH |
53 | inode->i_op = &sysfs_dir_inode_operations; |
54 | inode->i_fop = &sysfs_dir_operations; | |
e080e436 TH |
55 | inc_nlink(inode); /* directory, account for "." */ |
56 | unlock_new_inode(inode); | |
fc9f54b9 | 57 | |
e080e436 | 58 | /* instantiate and link root dentry */ |
1da177e4 LT |
59 | root = d_alloc_root(inode); |
60 | if (!root) { | |
61 | pr_debug("%s: could not get root dentry!\n",__FUNCTION__); | |
62 | iput(inode); | |
63 | return -ENOMEM; | |
64 | } | |
0b8ead82 | 65 | sysfs_root.s_dentry = root; |
1da177e4 LT |
66 | root->d_fsdata = &sysfs_root; |
67 | sb->s_root = root; | |
68 | return 0; | |
69 | } | |
70 | ||
454e2398 DH |
71 | static int sysfs_get_sb(struct file_system_type *fs_type, |
72 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 73 | { |
454e2398 | 74 | return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt); |
1da177e4 LT |
75 | } |
76 | ||
77 | static struct file_system_type sysfs_fs_type = { | |
78 | .name = "sysfs", | |
79 | .get_sb = sysfs_get_sb, | |
80 | .kill_sb = kill_litter_super, | |
81 | }; | |
82 | ||
83 | int __init sysfs_init(void) | |
84 | { | |
85 | int err = -ENOMEM; | |
86 | ||
87 | sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", | |
88 | sizeof(struct sysfs_dirent), | |
20c2df83 | 89 | 0, 0, NULL); |
1da177e4 LT |
90 | if (!sysfs_dir_cachep) |
91 | goto out; | |
92 | ||
93 | err = register_filesystem(&sysfs_fs_type); | |
94 | if (!err) { | |
95 | sysfs_mount = kern_mount(&sysfs_fs_type); | |
96 | if (IS_ERR(sysfs_mount)) { | |
97 | printk(KERN_ERR "sysfs: could not mount!\n"); | |
98 | err = PTR_ERR(sysfs_mount); | |
99 | sysfs_mount = NULL; | |
100 | unregister_filesystem(&sysfs_fs_type); | |
101 | goto out_err; | |
102 | } | |
103 | } else | |
104 | goto out_err; | |
105 | out: | |
106 | return err; | |
107 | out_err: | |
108 | kmem_cache_destroy(sysfs_dir_cachep); | |
109 | sysfs_dir_cachep = NULL; | |
110 | goto out; | |
111 | } |